JP2001242663A - Method of manufacturing electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an electrostatic charge image developing toner by which toner particles showing sharp distribution of the grain size with small proportions of fine particles and coarse particles can be obtained. SOLUTION: The method of manufacturing an electrostatic charge image developing toner includes an aggregation process of heating a mixture dispersion liquid containing at least binder primary particles, coloring agent particles and charge controlling agent particles to obtain aggregated particles. In this method, the form of the liquid surface during stirred in the aggregation process satisfies the formulae (I): HC<=0.5H and (II): 1.5H<=HE, wherein H is the distance between the horizontal surface of the mixture dispersion liquid in a normal state (not stirred) and the center bottom of the reaction tank, HC is the distance between the center liquid surface of the mixture dispersion liquid during stirred and the center bottom of the reaction tank, and HE is the distance between the edge liquid surface of the mixture dispersion liquid during stirred and the center bottom of the reaction tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner for electrostatic charge development used in an electrophotographic copying machine and a printer. More specifically, the present invention relates to a method for producing a toner for electrostatic charge development, in which the particle size is controlled in the aggregation step to obtain sharp toner particles having a small particle size distribution with little fine powder and coarse powder.

[0002]

2. Description of the Related Art An electrostatic image developing toner, which has been widely used in electrophotography, is a mixture of a resin containing a colorant such as carbon black or a pigment, a wax, and / or a magnetic material, which is melt-kneaded by an extruder. And then crush
It has been manufactured by classification. However, in the conventional toner obtained by the above-described melt-kneading / pulverizing method, it was difficult to disperse the raw materials. On the other hand, in recent years, high image quality and high speed have been demanded as the performance of printers and copiers. For higher image quality, it is necessary that the toner particle size is as small as 3 to 9 μm and the particle size distribution is narrow. In order to increase the speed, by increasing the fixing speed, that is, by setting the temperature to a low temperature, an environment-friendly printer or copier that does not generate high heat other than shortening the standby time and consumes less power is required. Machine can be realized.

[0003] In order to fix a toner at a low temperature, the softening point of the resin may be lowered. However, in the conventional toner obtained by the melt-kneading / pulverization method, the low-temperature fixability can be improved by lowering the softening point of the resin, but at the same time, the Tg of the toner decreases and the blocking resistance deteriorates. . That is, it was impossible to control the dispersion of the raw materials, and it was almost impossible to control the structure to achieve both the anti-blocking property and the low-temperature fixing property. There is also a method of mixing additives such as wax,
In melt kneading, there is a limit to the amount of additives to be added.
The amount was about 4 to 5 parts with respect to 0 part, and sufficient low-temperature fixability could not be added. Further, since the flakes obtained by melt-kneading are mechanically pulverized into toner, the smaller the particle size, the lower the yield and the worse the particle size distribution.

On the other hand, in recent years, a method for producing a polymerized toner by an emulsion polymerization coagulation method, a suspension polymerization method, or the like has been known as a production method replacing the melt kneading / pulverization method. When these methods are used, the dispersion of the raw materials can be controlled unlike the melt-kneading / pulverizing method. It is also possible to obtain a toner having a small particle size and a good particle size distribution. In particular, in the emulsion aggregation polymerization method, the particle size, the particle size distribution, and the toner shape can be controlled. When a toner is produced by an emulsion polymerization method, the particle diameter obtained by polymerization is 0.0
A pigment, a charge control agent, and the like are added to a resin emulsified dispersion containing resin primary particles of 5 μm to 0.5 μm, and an electrolyte and the like are further added to aggregate the primary particles to form toner particles of 3 to 9 μm. The slurry is washed and dried to obtain product toner particles. However, if the toner is simply stirred and aggregated in the aggregation step, toner particles having a uniform particle size cannot be obtained. The agitation step plays an important role in aggregating the primary particles, and the selection of blades that can cope with the change in viscosity during agglomeration is indispensable for controlling the agglomerated particles.
The control of the aggregated particles is not sufficient, and it is difficult to obtain a uniform toner having a small particle size. Even in the case of the toner obtained by the polymerization method, classification is further performed to achieve the desired performance. Needed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing an emulsion aggregation polymerized toner having a small particle size and a sharp particle size distribution in response to a change in viscosity during aggregation.

[0006]

Means for Solving the Problems As a result of diligent studies on the above-mentioned problems, the present inventors have found that the uniformity of mixing of the agglomerated liquid at the time of aggregating at the time of aggregating at the time of aggregating by stirring under constant conditions in the aggregating process of the toner. Surface, the sharp difference in the particle size distribution of the aggregated particles, from the ease of controlling the particle size, found that the above problems can be solved,
The present invention has been reached. That is, the gist of the present invention is at least
A method for producing an electrostatic image developing toner having an aggregation step of obtaining aggregated particles by heating a mixed dispersion containing binder primary particles, colorant particles, and charge control agent particles, wherein stirring is performed in the aggregation step. Wherein the liquid surface shape at the time satisfies the following formulas (I) and (II).

[0007]

H _C ≦ 0.5H (I), 1.5H ≦ H _E (II) H: Distance between the stationary mixed dispersion horizontal surface (when not stirred) and the bottom of the center of the reaction tank H _C : Distance between the liquid surface at the center of the mixed dispersion and the bottom of the reaction tank at the time of stirring _HE : The distance between the liquid surface at the end of the mixed dispersion and the bottom at the center of the reaction tank during stirring

[0008] Another gist of the present invention is to provide an electrostatic charge image having an aggregation step of adding aggregated particles by adding an electrolyte to at least a mixed dispersion containing primary binder particles, colorant particles, and charge control agent particles. A method for producing a toner for development, wherein the liquid surface shape at the time of stirring in the aggregation step satisfies the following formulas (I) and (II).

H _C ≦ 0.5H (I), 1.5H ≦ H _E (II) H: Distance between the stationary mixed dispersion horizontal surface (when not stirred) and the bottom of the center of the reaction tank H _C : Distance between the liquid surface at the center of the mixed dispersion and the bottom of the reaction tank at the time of stirring _HE : The distance between the liquid surface at the end of the mixed dispersion and the bottom at the center of the reaction tank during stirring

Another aspect of the present invention resides in a method for producing a toner for developing an electrostatic charge image, wherein the stirring blade used in the aggregation step is a helical blade.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below. The production of the toner of the present invention is based on the emulsion polymerization aggregation method.
When a toner is produced by an emulsion polymerization method, resin primary particles having a normal particle diameter of 0.05 μm to 0.5 μm obtained by polymerization (hereinafter sometimes referred to as binder primary particles).
Is mixed with a pigment, a charge control agent, and the like,
The primary particles are agglomerated into toner particles having a volume average particle diameter of 3 to 9 μm (hereinafter, the toner particles before washing may be simply referred to as agglomerated particles).
Dry to obtain product toner particles. Here, in the aggregation step, there are 1) a method of performing aggregation by heating, and 2) a method of performing aggregation by adding an electrolyte. When performing aggregation by heating, the aggregation temperature is specifically Tg-20 ° or more.
It is a temperature range of Tg (however, Tg is a glass transition temperature of the primary particles of the binder), and a range of Tg-10 ° to Tg-5 ° is preferable. Within the above temperature range, the toner can be aggregated to a preferable toner particle size without using an electrolyte. In addition, when aggregation is performed by adding an electrolyte, the aggregation temperature is preferably 20 ° to 40 °, more preferably 25 ° to 35 °.

In order to control the particle size of toner particles having a predetermined particle size (3 to 9 μm), the aggregation temperature is usually maintained at a predetermined temperature for at least 30 minutes to 1 hour, so that toner particles having a desired particle size can be obtained. I do. The temperature may be raised at a constant rate up to a predetermined temperature, or may be raised stepwise. Further, in order to increase the stability of the aggregated particles (toner particles) obtained by the aggregation, it is preferable to add a ripening step of causing fusion between the aggregated particles in the range of Tg + 20 ° to Tg + 80 °. By adding the aging step, the shape of the toner particles can be made nearly spherical, and the shape can be controlled. This aging step is usually performed for 1 hour to 24 hours, preferably 2 hours to 10 hours. The ratio of the volume average particle diameter (D _V ) of the toner thus obtained to the number average particle diameter (D _N ) is preferably D _V : D _N = 1.6: 1 to 1.
1: 1, more preferably D _V : D _N = 1.5: 1.
１．１1.1: 1. In the method for producing a toner of the present invention,
This is particularly effective when producing a toner having such a good particle size distribution.

As the binder resin used in the emulsion polymerization coagulation method, conventionally known binder resins can be used, and preferred are styrene-acrylate copolymers, styrene-methacrylate copolymers, or these resins. Styrene-based polymers such as acrylic acid copolymers, saturated or unsaturated polyester-based polymers, and epoxy-based polymers. The binder resin is not limited to being used alone, and two or more binder resins can be used in combination. The binder resin is made into resin primary particles by emulsion polymerization, and is used in the aggregation step. A resin obtained by seed polymerization using wax fine particles as seeds can also be used.

The coloring agent may be any of conventionally known inorganic or organic pigments and organic dyes, or a combination thereof. Specific examples of these include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dyes, monoazo dyes, disazo dyes System, condensed azo dyes and pigments,
Any known dyes and pigments can be used alone or in combination. In the case of a full-color toner, it is preferable to use benzidine yellow, monoazo-based and condensed azo-based dyes and pigments for yellow, quinacridone and monoazo-based dyes and pigments for magenta, and phthalocyanine blue for cyan, respectively. The colorant is generally used in an amount of 3 to 100 parts by weight of the binder resin.
Used to be 20 parts by weight. The average particle size of the colorant in the mixed dispersion is preferably from 0.05 to 3 μm, more preferably from 0.1 to 1 μm.

As the charge control agent, any known charge control agent can be used alone or in combination. Considering the color toner adaptability (the charge control agent itself is colorless or light color and there is no color hindrance to the toner), the quaternary ammonium salt compound is used as the positive charge, and the chromium of salicylic acid or alkyl salicylic acid is used as the negative charge. ,zinc,
Preferred are metal salts and metal complexes with aluminum and the like, metal salts and metal complexes of benzylic acid, amide compounds, phenol compounds, naphthol compounds, phenolamide compounds and the like. The average particle size of the charge control agent in the mixed dispersion is 0.1.
0.01 to 1 μm, preferably 0.05 to 0.8
More preferably, it is μm. If the average particle size is significantly larger than the above range, the required amount for exhibiting good chargeability and charge stability tends to be large, and the adhesion tends to be weak. Further, for the same reason, the maximum particle size is preferably 3 μm or less, and those having a good particle size distribution are preferable.
The particle size distribution and the average particle size can be measured using various types of fine particle measuring devices (for example, UPA manufactured by Microtrac Co., Ltd.).

The amount of charge control agent used may be determined according to the desired charge amount of the toner.
The amount is usually 0.001 to 5 parts by weight, preferably 0.003 to 2 parts by weight, more preferably 0.01 to 0 parts by weight.
Use up to 1 part by weight. According to the production method of the present invention, the charge control agent can be securely adhered to the toner surface, so that good chargeability and charge stability can be exhibited with a smaller amount than usual. By using the production method of the present invention, the charge control agent to be used can be suppressed to a small amount, and the toner can be produced at lower cost.

Further, if necessary, the toner for developing an electrostatic image may contain a wax. As the wax, any known wax can be used. Specifically, olefin-based waxes such as low-molecular-weight polyethylene, low-molecular-weight polypropylene, and copolymerized polyethylene, paraffin wax, behenyl behenate, montanic acid ester Ester wax having a long-chain aliphatic group such as stearyl stearate, vegetable wax such as hydrogenated castor oil, carnauba wax, ketone having a long-chain alkyl group such as distearyl ketone, silicone having an alkyl group, stearic acid And higher-chain fatty acid alcohols, long-chain fatty acid polyhydric alcohols such as pentaerythritol, and partial esters thereof, higher fatty acid amides such as oleamide and stearamide. Wax is usually used in binder resin 10
It is used in an amount of 1 to 25 parts by weight with respect to 0 parts by weight.

As a method for incorporating a wax into a toner, wax fine particles are further mixed with a mixed dispersion containing primary binder particles, colorant particles, and charge control agent particles, and an electrolyte is added thereto to form aggregated particles. In addition to the above method, when preparing the above-mentioned binder primary particles, wax fine particles are added to a monomer containing a monomer having an acidic polar group or a basic polar group, and the wax fine particles are seed-polymerized as a seed. Wax can be contained in the primary particles of the binder. When the wax fine particles are mixed in the mixed dispersion, the average particle diameter of the wax fine particles is 0.03.
１1 μm, preferably 0.05-0.8 μm
Is more preferable. When the primary particles of the binder are contained as seeds, the average particle diameter of the wax fine particles is preferably from 0.03 to 1 μm, and more preferably from 0.05 to 0.8 μm.
The particles of each of the above components are dispersed in water using an emulsifier to form a mixed dispersion. As the emulsifier, at least one emulsifier selected from known cationic surfactants, anionic surfactants, and nonionic surfactants can be used. Two or more of these surfactants may be used in combination.

Specific examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide and the like. Specific examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, and sodium dodecylbenzenesulfonate. Further, specific examples of the nonionic surfactant include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, nonylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, and styrylphenyl poly. Oxyethylene ether, monodecanoyl sucrose and the like. Of these, anionic surfactants and / or nonionic surfactants are preferred. In addition, a protective colloid can be used as a dispersion stabilizer. Specific examples of the protective colloid include polyvinyl alcohols, cellulose derivatives,
Natural polysaccharides, calcium phosphate, tricalcium phosphate,
Examples include magnesium phosphate, calcium hydroxide, magnesium hydroxide and the like.

The particles of the colorant, the charge control agent, and, if necessary, the components of the wax are mixed and dispersed in the primary particle dispersion of the binder.
That is, it is preferable to prepare a dispersion of a colorant, a dispersion of a charge control agent, and a dispersion of wax fine particles if necessary, and to obtain a mixed dispersion by mixing these. The charge control agent dispersion is
It may be added during the aggregation step, or may be added after the particles have been grown to the final toner particle size. As an electrolyte in the case of performing aggregation by adding an electrolyte to the mixed dispersion,
Either an organic salt or an inorganic salt may be used, but a monovalent or divalent or higher polyvalent metal salt is preferably used. Specifically, NaCl, KCl, LiCl, Na ₂
SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ , CaC
l ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , Al ₂ (SO
₄ ) ₃ , Fe ₂ (SO ₄ ) _{3 and the} like.

The amount of the electrolyte to be added varies depending on the type of the electrolyte, but is usually 0.05 to 25 parts by weight based on 100 parts by weight of the solid component of the mixed dispersion. Preferably 0.1 to 15 parts by weight, more preferably 0.1 to 10 parts by weight
Parts by weight. When the amount of the electrolyte added is significantly smaller than the above range, the progress of the agglutination reaction is slowed down and the
Problems tend to occur, such as fine powder having a particle size of μm or less remaining, or an average particle size of the obtained aggregated particles being 3 μm or less.
On the other hand, when the amount of the electrolyte added is significantly larger than the above range, agglomeration tends to occur rapidly and is difficult to control. It tends to cause problems such as becoming fixed-shaped objects. The mixed dispersion is heated or an electrolyte is added to agglomerate the particles of each component to obtain agglomerated particles. In this aggregating step, each component is uniformly agglomerated and the agglomerated particles are reduced to a small particle size. In order to control the particle size distribution, it is necessary to stir the mixed dispersion evenly and with appropriate intensity. However, the coagulation step of the emulsion polymerization coagulation method is a slurry in which particles of various components are dispersed, and the viscosity of the liquid is relatively high, so that it is difficult to control the stirring uniformly and with appropriate strength. there were. In the production method of the present invention, the shape of the liquid surface in the aggregation step is such that the following formulas (I) and (II) are obtained.

[0021]

H _C ≦ 0.5H (I), 1.5H ≦ H _E (II) H: Distance between the stationary mixed dispersion horizontal surface (when not stirred) and the bottom of the center of the reaction tank H _C : Distance between the liquid surface at the center of the mixed dispersion and the bottom of the reaction tank at the time of stirring _HE : The distance between the liquid surface at the end of the mixed dispersion and the bottom at the center of the reaction tank during stirring

In the present invention, the liquid surface shape represented by the above formulas (I) and (II) may be taken in any part of the aggregation step. Means that at least the temperature at the time of stirring is Tg-20 ° (however, Tg
g is the glass transition temperature of the primary particles of the binder) for 30 minutes, and when coagulation is performed by adding an electrolyte, the above formula (I) is used for 30 minutes after the addition of the electrolyte is started.
And (II). It is more preferable that the liquid surface shapes represented by the above formulas (I) and (II) are also taken at the start of the aggregation step. Specifically, when performing aggregation by heating, Tg Between −25 ° and Tg−20 °, and in the case of performing aggregation by adding an electrolyte, it is one minute immediately before the start of adding the electrolyte. It is most preferable to take the liquid surface shapes represented by the above formulas (I) and (II) until the end of the aggregation step, that is, until the stirring is completed.

The liquid surface shapes represented by the above formulas (I) and (II) will be specifically described with reference to the drawings. FIG. 1 shows a liquid surface in an unstirred state, and the liquid surface of the mixed dispersion is a horizontal surface. Here, as the reaction tank, an ordinary substantially cylindrical one or a substantially spherical one is preferably used. When the reaction tank is substantially cylindrical, the shape of the bottom surface is not particularly limited, but an ordinary substantially arc-shaped one is preferably used. FIG.
Shows a typical container preferably used.
The ratio of the height of the reaction tank (total height inside the reaction tank: L) to the width (total width: D) is preferably L: D = 5: 1 to 1: 2, and L: D = 4: 1. ~ 1: 1 is more preferred. Further, depending on the shape of the stirring blade used, a baffle (baffle plate) may be provided in the reaction tank, but it is preferable to provide a baffle inside the stirring blade using a stirring blade having no central axis. In order to improve the stirring efficiency, the volume of the mixed dispersion is preferably 以下 or less of the volume of the reaction tank,
/ 5 or less is more preferable. Also, if the volume of the mixed dispersion is extremely small compared to the volume of the reaction solution, bubbling is intense, thickening is increased, coarse powder particles are likely to be generated, and depending on the shape of the stirring blade, stirring may not be performed. This ratio is preferably 1/10 or more, more preferably 1/5 or more, since the production efficiency is also lowered.

FIG. 2 shows an example of the liquid level of the mixed dispersion in a stirring state. Upon stirring, a normal reaction liquid takes a shape in which the liquid level is lowered at the center and the liquid level is raised at the ends, as shown in FIG. However, in the production of the toner by the emulsion polymerization aggregation method, as described above, since the particles of each component are dispersed and the viscosity of the liquid is high, air is taken in during normal stirring to foam (FIG. 3). ). In the stirring state as shown in FIG. 3, only the mixed dispersion in the vicinity of the stirring blade is stirred, and in the portion far from the stirring blade, the stirring is hardly performed. The result can be done. Therefore, it is necessary to control the stirring state as shown in FIG. 2 even for the slurry.

Next, each symbol in the above formulas (I) and (II) will be described. H represents the distance between the horizontal surface of the stationary mixed dispersion liquid (when not stirred) and the bottom of the central portion of the reaction tank. And are shown in FIG. When a discharge port or the like is arranged on the bottom of the central portion of the reaction tank, the distance from the mixed dispersion is measured not from the lower portion of the discharge port or the like but from the substantially bottom of the container. Here, H represents the distance between the horizontal surface of the stationary mixture dispersion liquid (when not stirred) and the bottom of the center of the reaction tank. Specifically, in the reaction tank, resin primary particles, colorant, wax, charge control The measurement is performed before stirring with the mixed dispersion containing each component of the agent introduced. When any part of the component such as the charge control agent dispersion is introduced in the middle of the stirring, a steady mixture dispersion horizontal surface and the reaction tank are assumed assuming that the mixed dispersion is completely introduced into the reaction tank. Indicates the distance from the center bottom. H _C is the distance of the mixed dispersion central liquid surface at the time of stirring and the reaction vessel central bottom, H _E represents the distance of the mixed dispersion liquid end liquid face during stirring and the reaction vessel central bottom, FIG. 2
And in FIG. Also in this case, when a discharge port or the like is arranged on the bottom surface of the central portion of the reaction tank, the distance from the mixed dispersion is measured not from the lower portion of the discharge port or the like but from the substantially bottom surface as a container.

Further, when the mixed dispersion is foamed becomes a liquid surface shape shown in FIG. 3, and the liquid surface, the distance between the reaction vessel central bottom (H _C, H _E), including foamed portion And measure.
Therefore, according to the formulas (I) and (II), both the case where the stirring speed is not sufficient due to the insufficient rotation speed of the stirring blade and the case where the stirring is not performed uniformly due to foaming, can be considered from the production method of the present invention. Be distinguished. Although the reason why the production method of the present invention exerts the above-described excellent effects is not necessarily clear, the particle size at the time of aggregation is such that a network is formed at the time of aggregation and the viscosity increases, and the particle size is determined by the magnitude of the shearing force of the stirring blade. It is estimated that the particle size distribution is determined by the mixing uniformity at the time of thickening. In order to secure the mixing uniformity, the above formulas (I) and (II) in which foaming is suppressed and a suitable shear force is maintained. It is presumed that the condition that satisfies is necessary and effective.

The reaction tank used in the aggregation step is usually
A stirring tank type is used. In addition, as the stirring blade, as long as the stirring conditions of the above formulas (I) and (II) are satisfied, conventionally known and commercially available stirring blades having various shapes can be used. Commercially available stirring blades include, for example, anchor blades (manufactured in-house), full zone blades (manufactured by Shinko Pantech), sun meller blades (manufactured by Mitsubishi Heavy Industries, Ltd.), Max Blend blades (manufactured by Sumitomo Heavy Industries, Ltd.), and Hi-F. Stirring blades such as mixer blades (manufactured by Soken Chemical Co., Ltd.), double helical blades (manufactured by Shinko Pantech Co., Ltd., in-house co-produced), and double helical blades with baffles can be mentioned.

Normally, these stirring blades are selected and used depending on the viscosity and other physical properties of the reaction solution, the reaction form, and the like. In practice, however, in the aggregation step of the emulsion polymerization aggregation method, the formula (I) is used. It is quite difficult to select a stirring blade to meet the requirements. However, among the above-mentioned stirring blades, it is preferable that the projection area from above the stirring blade is relatively larger than the projection area from the side, specifically, the projection area from above (S _U ). Projected area from the side (S _S )
Are in the range of S _U : S _S = 5: 1 to 1: 1.
In addition, each projection area measures the part which is in contact with the mixed dispersion liquid without stirring.

More specifically, a preferred shape of the stirring blade is a helical blade. Among the helical blades, a helical ribbon blade having no central axis is preferable. Further, in the case of a helical blade, there are a single helical having one spiral structure, a double helical having two spiral structures, and a triple or more. However, considering the stirring efficiency and the manufacturing surface of the helical blade, it is considered. , A double helical wing is preferred.

In the case of a helical blade, the pitch (the ratio of the horizontal width in one spiral structure to the vertical width including one period) is:
Width: length = 1: 1 to 1: 2 is preferred. In addition, it is preferable to provide a baffle (baffle) in the reaction tank for the purpose of ensuring uniformity of stirring. The baffle is provided outside the wing in the case of a wing having a central axis. In addition, when a blade having no center axis is used, it is preferable to provide the blade inside the blade.

[0031]

The present invention will be described more specifically with reference to the following examples. In the following examples, “parts” means “parts by weight”. The average particle diameter of the aggregated particles was measured by the following method. Average particle size: Measured using a SALD2000J laser diffraction type particle size distribution meter manufactured by Shimadzu Corporation.

(Emulsion polymerization dispersion: preparation of binder primary particle dispersion) Sodium dodecylbenzenesulfonate (sodium dodecylbenzenesulfonate) was placed in a glass reactor equipped with a stirrer, a heating / cooling device, a concentrating device, and a device for charging raw materials and auxiliaries. 0.268 parts and 367 parts of deionized water were charged and heated to 90 ° C. under a nitrogen stream. Thereafter, the following initiator-1 was added, monomers + DBS + deionized water were added in 5 hours, and initiator-2 was added in 6 hours to carry out emulsion polymerization.

[0033]

<Table 1> <Monomers> Styrene 79 parts Butyl acrylate 21 parts Acrylic acid 3 parts Trichlorobromomethane 0.5 parts <Emulsifier> DBS 0.27 parts 1% nonionic surfactant 0.01 parts Deionized water 22 Part <initiator-1> 8% aqueous hydrogen peroxide 0.13 part 8% aqueous ascorbic acid 0.13 part <initiator-2> 8% aqueous hydrogen peroxide 0.72 part 8% ascorbic acid aqueous solution 0.72 Department

After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white binder primary particle dispersion (A). The average particle size of the obtained emulsion is 188 nm (UPA manufactured by Microtrac Co., Ltd.).
Mw of the polymer was 71,000 and Mp was 54,000.

[0035]

(Production of agglomerated particles) Binder primary particle dispersion (A) 100 parts (solid content) Blue dye EP700BlueGA (30% dispersion: manufactured by Dainichi Seika Co., Ltd.) 6.7 parts (solid content) Wax HYTEC E -433N (30% dispersion: Toho Chemical Co., Ltd.) 5 parts (solid content) 20% dispersion of charge control agent 4,4'-methylenebis [2-N- (4-chlorophenyl) amide] -3-hydroxynaphthalene] 0.1 part of liquid (solid content)

[Example 1] Double helical ribbon blades (with two inner φ10 round bar baffles; blade diameter 90 mm; blade width 9 mm; rotation speed 500 rpm) in a glass separable flask (inner diameter 100 mm × height 300 mm) flocculation tank Is set, and the mixture of the above-mentioned dispersion liquid is dispersed and stirred with a double helical ribbon blade from 1 to 25 ° C. at 1 ° C./min.
And hold for 2 hours, hold at 65 ° C. for 2 hours, then add a charge control agent, hold at 72 ° C. for 1 hour,
C. for 1 hour and further at 90.degree. C. for 1 hour. When the volume average particle diameter was measured by a laser diffraction type particle size distribution analyzer at each temperature, the particle diameter was stable at about 6 μm from 65 ° C. to 90 ° C., and the particle diameter was stable. Even during the temperature raising process, the particle size did not change, and the components were uniformly stirred and mixed. Further, the particle size distribution of the aggregates was narrow and small. In addition, the entrapment of bubbles during thickening was small.

Comparative Example 1 The double helical ribbon blade used in Example 1 was replaced with an anchor blade (wing diameter 93 mm; blade width 10 m).
m; the number of rotations was changed to 480 rpm), except that the aggregation step was performed in the same manner as in Example 1. The volume average particle size at 90 ° C. was 20.0 μm, the particle size distribution was wide, the particle size was large, and the Was heterogeneous mixing. In addition, bubbles were involved, and the thickening was too severe, and only the stirring blade was idle. [Comparative Example 2] The double helical ribbon blade used in Example 1 was replaced with a Hi-F mixer blade (blade diameter 62 mm; rotation number 610).
aggregating step was performed in the same manner as in Example 1 except that the volume average particle diameter at 90 ° C. was 11.7 μm.
m, the particle size distribution was wide, the particle size was large, and non-uniform mixing with stirring had occurred. In addition, bubbles were involved, and the thickening was too severe, and only the stirring blade was idle. Comparative Example 3 The double helical ribbon blade used in Example 1 was replaced with a Sun Meller blade (blade diameter: 60 mm; rotation speed: 630 rpm)
m), the agglomeration step was performed in the same manner as in Example 1. The volume average particle size at 90 ° C. was 11.7 μm, the particle size distribution was wide, the particle size was large, and the mixture was not uniformly mixed. Was happening. In addition, bubbles were involved, and the thickening was too severe, and only the stirring blade was idle. Each example, H _C in the comparative example, the value of H _E and, Shimadzu Corp. SALD200
Table 1 below shows the average particle size and the positive value of the volume average value / number average value at the end of aggregation by a 0J laser diffraction type particle size distribution meter.

[0038]

[Table 3]

[0039]

According to the present invention, the mixing uniformity at the time of thickening is improved, and it is possible to produce toner particles having a small aggregate particle size and a narrow particle size distribution. Further, since a classification step is not required, a toner can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 shows a mixed dispersion (slurry) in a reaction vessel in an unstirred state.

FIG. 2 is an embodiment of the production method of the present invention, and shows a mixed dispersion (one that has not been fired) in a stirred reaction tank.

FIG. 3 shows a mixed dispersion (foamed) in a stirred reaction tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction tank 2 Mixed dispersion (slurry) 3 Outlet 4 Mixed dispersion which was shot

Claims (8)

[Claims] 1. A method for producing a toner for developing an electrostatic charge image, which comprises an aggregating step of heating at least a mixed dispersion containing primary binder particles, colorant particles and charge control agent particles to obtain aggregated particles. A method for producing a toner for developing an electrostatic image, wherein the liquid surface shape at the time of stirring in the aggregation step satisfies the following formulas (I) and (II). H _C ≦ 0.5H (I), 1.5H ≦ H _E (II) H: Distance between the stationary mixed dispersion horizontal surface (when not stirred) and the bottom of the center of the reaction tank H _C : Distance between the liquid surface at the center of the mixed dispersion and the bottom of the reaction tank at the time of stirring _HE : The distance between the liquid surface at the end of the mixed dispersion and the bottom at the center of the reaction tank during stirring 2. A method for producing a toner for developing an electrostatic charge image, comprising an aggregating step of obtaining an agglomerated particle by adding an electrolyte to a mixed dispersion containing at least a primary binder particle, a colorant particle and a charge control agent particle. Wherein the liquid surface shape at the time of stirring in the aggregation step satisfies the following formulas (I) and (II): H _C ≦ 0.5H (I), 1.5H ≦ H _E (II) H: Distance between the stationary mixed dispersion horizontal surface (when not stirred) and the bottom of the center of the reaction tank H _C : Distance between the liquid surface at the center of the mixed dispersion and the bottom of the reaction tank at the time of stirring _HE : The distance between the liquid surface at the end of the mixed dispersion and the bottom at the center of the reaction tank during stirring 3. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the primary particles of the binder are obtained by seed polymerization of a monomer using wax fine particles as seeds. 4. The method according to claim 3, wherein the monomer contains a compound having an acidic polar group or a basic polar group. 5. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the mixed dispersion further contains wax fine particles in addition to the binder primary particles, the colorant particles, and the charge control agent particles. 6. The method according to claim 1, wherein the stirring blade used in the aggregation step is a helical blade. 7. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the volume average particle diameter of the toner is 3 to 9 μm. 8. The ratio of the volume average particle diameter (D _V ) to the number average particle diameter (D _N ) of the toner is D _V : D _N = 1.6: 1 to 1.
8. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the ratio is 1: 1.